Various navigation systems provide users with turn-by-turn directions. These systems include handheld GPS devices, mobile phones, or vehicle-mounted devices. A user inputs one or more locations and receives a route and turn-by-turn directions based on the inputted locations. The user may follow the turn-by-turn directions to reach the one or more locations.
These navigation systems rely on the ability to receive information from a plurality of GPS satellites. This allows for identification of a current location of a device for providing navigational assistance. However, while indoors, a mobile device may require accurate localization to enable features such as advanced indoor navigation, for example, to conference rooms in a building or stores within a mall. In an indoor environment, accurate localization is difficult due to the lack of adequate signals from the GPS satellites.
In the field of robotics, particle filters or other probabilistic approaches may be used to identify the location of a robot which has no information regarding its location other than a map. This is generally referred to as the “kidnapped robot problem.” These robots use sophisticated cameras and lasers to take measurements. These measurements are used in conjunction with the particle filter to reduce the number of possible map locations until only a single possible location is left. However, while many modern smart phones incorporate a significant amount of technological advancements, they typically do not include the sophisticated cameras and lasers generally utilized to solve the kidnapped robot problem.